Polymers and other organic materials are susceptible to degradation by oxidation due to heat etc. if left as they are, so to improve their heat resistances, various antiaging agents are added to obtain heat resistances according to the particular objectives. As such antiaging agents, for example, diphenylamine-based antiaging agents which are described in Patent Documents 1 to 3 are widely known.
In this regard, in recent years, polymers and other organic materials have been increasingly used at tougher high temperatures. For example, for the rubber materials which are used around the engines of automobiles, the temperatures in the engine compartments have been rising as a general trend due to the higher outputs of automobile engines and the appearance of low pollution engines etc. Therefore, the rubber materials which are used in their surroundings are required to exhibit better heat resistance.
Therefore, as one measure for achieving this object, development of a new antiaging agent which has a better effect than conventional diphenylamine-based antiaging agents has been desired.